Laryngeal mask

ABSTRACT

A laryngeal mask of the type used to facilitate lung ventilation and the insertion of endo-tracheal tubes or related medical instruments through a patient&#39;s laryngeal opening as used during general anesthesia, intensive care, or critical patient care. The mask includes an inflatable positioning shield formed to fit within a patient&#39;s oropharynx and seal around the circumference of the laryngeal opening, the shield having an inflatable annular toroid peripheral portion, a contoured rear portion, and a recessed front. The mask also includes a flexible respiratory tube having an proximal end lumen, a gently curved tubular body of sufficient size to permit passage of endo-tracheal tubes, and related medical instruments, and a distal end passing through and secured to the proximal edge of the annular toroid peripheral portion. The distal end of the tube terminates at a distal lumen within the recessed front of the inflatable positioning shield such that tubes and instruments passing through the flexible respiratory tube will be directed into the laryngeal opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

This invention relates to an artificial airway device designed tofacilitate lung ventilation and the insertion of endo-tracheal tubes orrelated medical instruments into the laryngeal opening of an unconsciouspatient, and more specifically, to a laryngeal mask device designed tobe placed within the oropharynx region over the laryngeal opening, andsecured by means of air inflation, thereby sealing the circumference ofthe laryngeal opening against the aspiration of regurgitated gastriccontents and providing a direct pathway from a point exterior to theoral cavity to the laryngeal opening.

In general, laryngeal masks allowing for both rapid lung ventilation andthe insertion of medical instruments and tubes into the laryngealopenings of patients have been described in patents such as Brain, U.S.Pat. No. 4,509,514. Consisting of two essential parts, a breathing tubeand an inflatable mask, these devices are inserted blindly into apatient's throat, and when properly positioned, terminate at thelaryngeal opening. A seal is then formed around the circumference of thelaryngeal opening by the inflation of a ring-like structure located onthe front of the mask. Inflation of the ring exerts pressure againstboth the front and rear portions of the oropharynx, securing the devicein place such that the laryngeal opening is positioned within a recessedcavity in the mask face. Extending from a point external to the oralcavity, the flexible breathing tube terminates within the recessedcavity, aligned axially with the laryngeal opening. The positioning ofthe flexible breathing tube allows the passage of small diameterendo-tracheal tubes or related medical instruments into the laryngealopening, in addition to allowing for lung ventilation.

Current laryngeal masks have several drawbacks in the areas ofplacement, lung ventilation, and endo-tracheal intubation. For example,during insertion and positioning, the flexible nature of the deflatedring structure and surrounding mask may allow the distal end of the maskto bend back on itself, preventing proper inflation and the formation ofa tight seal. Also, once successfully installed, the current maskdesigns may fail to exert sufficient pressure against the larynxnecessary to maintain proper positioning during intubation andventilation. This is due to the variations in anatomy of the oropharynxregion, the muscular tension against which the mask is exertingpressure, and the curvature of the device itself.

During lung ventilation, it is possible for the tip of the epiglottis tobecome lodged in the distal lumen of the flexible breathing tube,preventing the passage of air or endo-tracheal tubes. This problem isoften overcome by the placement of a series of band structures at theentrance to the distal lumen, preventing the epiglottis from enteringthe breathing tube. However, these band structures severely restrict thesize of endo-tracheal tubes and related medical devices which may bepassed through the flexible breathing tube. Furthermore, after theinsertion of an endo-tracheal tube or related medical device, it oftenbecomes difficult to remove the laryngeal mask from the patient'soropharynx without dislodging or accidentally extracting theendo-tracheal tube or medical device along with the laryngeal mask.

The removable laryngeal mask of the present invention overcomes theseproblems and is distinguished from the prior art by providing generallythe same function as described above yet allowing a more secure andcertain insertion, allowing the unrestricted passage of large diameterendo-tracheal tubes directly to the laryngeal opening, and providingalternate airways to prevent blockage of the flexible breathing tubeduring patient ventilation.

SUMMARY OF THE INVENTION

Among the several objects and advantages of the present inventioninclude:

The provision of a new and improved laryngeal mask for the facilitationof lung ventilation and the insertion of endo-tracheal tubes and relatedmedical instruments into the laryngeal opening;

The provision of the aforementioned laryngeal mask which includes aflexible breathing tube portion and an inflatable mask portion, eachgently curved along a single arcuate curve for ease of insertion andpositioning;

The provision of the aforementioned laryngeal mask which includes anair-tight seal securing the inflatable mask to the distal end of theflexible breathing tube, said mask contoured to the anatomy of theoropharynx region of the throat;

The provision of the aforementioned laryngeal mask which includes astiff support structure for the inflatable mask formed by the distal endof the breathing tube, and a contoured rear surface on the inflatablemask, both aiding in the insertion and positioning of the device withinthe oropharynx;

The provision of the aforementioned laryngeal mask which includes aperforated extension of the flexible breathing tube within theinflatable mask portion so as to provide alternate airways in the eventthe distal lumen is blocked;

The provision of the aforementioned laryngeal mask which includes aflexible breathing tube having an elliptical cross-section, composed ofa deformable, low friction material so as to permit the passage of largediameter endo-tracheal tubes and related medical instruments;

The provision of the aforementioned laryngeal mask which includes anendo-tracheal tube retainer for use in conjunction with the laryngealmask and endo-tracheal tubes, the endo-tracheal tube retainerfacilitating the removal of the laryngeal mask from a patient'soropharynx without the accidental displacement of any insertedendo-tracheal tubes; and

The provision of the aforementioned laryngeal mask which includes anendo-tracheal tube retainer which may also be placed in a patient'soropharynx and serve as an intubating stylet.

Briefly stated, the removable laryngeal mask of the present invention isprimarily intended to facilitate lung ventilation and the insertion ofendo-tracheal tubes or related medical instruments into a patient'strachea as needed during general anesthesia, intensive care, or criticalpatient care. The removable laryngeal mask comprises a flexibleventilation tube and an inflatable positioning shield conforming to theanatomy of the oropharynx region surrounding the laryngeal opening, andsecurely affixed to the distal end of the ventilation tube. A separateendo-tracheal tube retainer facilitates removal of the laryngeal maskfrom the patient's oropharynx without dislodging any endo-tracheal tubesor related medical instruments passing through the laryngeal mask intothe patient's trachea.

The flexible ventilation tube of the laryngeal mask is gently curvedalong an arc approximating the curvature of the passage from a patient'soral cavity to the laryngeal region. The ventilation tube is ofsufficient length that the tube terminates exterior to the oral cavityafter proper insertion and positioning of the laryngeal mask, therebyallowing endo-tracheal tubes and related medical devices to be easilyinserted or attached. The ventilation tube is composed of a low-frictionelastic plastic polymer, and has an elliptical cross section closelyconforming to the actual cross section of the human throat. Largediameter endo-tracheal tubes and related medical instruments may passfreely through the flexible ventilation tube due to the low frictionnature of the plastic polymer and the ability of the tube to deform toaccommodate the larger diameter medical instruments. Passing through therear portion of the inflatable positioning shield, the flexibleventilation tube terminates at an angle to the length of the tube,creating an elongated distal lumen open to the front recess of theinflatable positioning shield. The elongated distal portion of theventilation tube forming the distal lumen serves the additional functionof providing a semi-rigid substructure onto which the inflatablepositioning shield is secured.

In addition to the elongated elliptical distal lumen, the peripheralsurface of the flexible ventilation tube distal end contains numerousauxiliary ventilation lumen open to the front recess of the inflatablepositioning shield. These auxiliary ventilation lumens function toprovide alternate air passageways in the event the primary distal lumenbecomes obstructed during the use of the laryngeal mask. Airflow throughthe auxiliary ventilation lumen prevents the formation of a pressuregradient between the ventilation tube and the front recess, therebypreventing any obstructing material from becoming lodged within thedistal lumen.

Secured to the elongated distal portion of the flexible ventilation tubeby an air-tight seal, the inflatable positioning shield serves to securethe laryngeal mask within a patient's oropharynx, adjacent the trachealopening. The inflatable positioning shield is composed of an inflatableannular toroid, a recessed front cavity, and several semi-rigidstructures molded to fit the anatomy of the laryngeal region. Duringinsertion of the laryngeal mask, the inflatable annular toroid isdeflated, reducing the overall size of the laryngeal mask andfacilitating proper insertion. Upon positioning adjacent the laryngealopening, the annular toroid is inflated by means of an externallyconnected air passage, conforming to the actual and potential spacesurrounding the rear and peripheral portions of the ventilation tubedistal lumen. The inflated annular toroid exerts pressure against thestructures of the oropharynx, forming a tightly sealed recessed frontcavity surrounding the elongated elliptical distal lumen and thelaryngeal opening. A pair of raised longitudinal ridges on the rearsurface of the inflatable positioning shield and a frontal notchconforming to the tracheal anatomy further serve to aid in maintainingproper positioning of the laryngeal mask after inflation by preventinglateral movement within the oropharynx cavity. The ridges alsofacilitate placement by reducing drag.

Upon proper inflation, endo-tracheal tubes and related medical devicespassing through the flexible ventilation tube exit the elongated distallumen axially aligned for entry into the laryngeal opening. Removal ofthe laryngeal mask from the oropharynx may be accomplished withoutdislodging any inserted endo-tracheal tubes or related medical deviceswith the aid of an endo-tracheal tube retaining device. The retainingdevice, composed of a narrow semi-rigid rod with a softer and pliablecap at one end and a tapered connection adapter at the other, isinserted through the laryngeal mask into the proximal end of anendo-tracheal tube until the tapered connection adapter is securelyfitted within the tube. As the laryngeal mask is withdrawn from thepatient's oropharynx, the endo-tracheal tube retaining device maintainsthe proper positioning of the endo-tracheal tube by allowing arestraining force to be exerted counter to the friction force associatedwith the withdrawal of the laryngeal mask. Once clear of the oralcavity, the laryngeal mask is slipped off the proximal end of theendo-tracheal tube retaining device, allowing the endo-tracheal tube orrelated medical instrument to remain properly positioned within thelarynx. Finally, the semi-rigid rod of the endo-tracheal tube retainingdevice can also be used as an intubating stylet for any further medicaldevices which need to be passed through the oropharynx and into theinserted endo-tracheal tube after removal of the laryngeal mask. Ofcourse the rod can also be used separately as an intubating stylet fordirect visualization.

These and other objects and advantages of the present invention willbecome more apparent from the description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a top view of the laryngeal mask of the present inventionillustrating the flexible breathing tube and the inflatable positioningshield;

FIG. 1A is a cross-sectional view taken along line 1A--1A in FIG. 1;

FIG. 2 is a side view of the inflatable positioning shield afterinflation;

FIG. 3 is a sectional view of the inflatable positioning shield afterinflation, taken along line 3--3 of FIG. 1;

FIG. 4 is bottom view of the inflatable positioning shield;

FIG. 5 is a sectional view of the inflatable positioning shield afterinflation, taken along line 5--5 of FIG. 4, illustrating the recessedfront of the positioning shield and the unobstructed distal lumen of theflexible breathing tube;

FIG. 6 is a rear view of the inflatable positioning shield afterinflation, with the flexible breathing tube removed;

FIG. 7 is an artists rendition of a patient's oral cavity, illustratingthe elliptical nature of the opening into the oropharynx region;

FIG. 8 is a plan view of the endo-tracheal tube retainer, illustratingthe soft cap portion;

FIG. 9 is a plan view of the endo-tracheal tube retainer, illustratingthe separation of the tube retainer body from the connection adapter;

FIG. 10 is a front view of the distal end of the connection adapters,illustrating the air-flow grooves;

FIG. 11 is a plan view of the laryngeal mask of the present inventionduring use, showing interaction with an endo-tracheal tube and theendo-tracheal tube retainer;

FIG. 12 is a plan view of endo-tracheal tube retainer during use,illustrating proper position of the tube retainer within anendo-tracheal tube; and

FIG. 13 is a plan view of the laryngeal mask of the present inventionduring removal, illustrating the operation of the endo-tracheal tuberetainer.

Corresponding reference numerals will be used throughout the severalfigures of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description illustrates the invention by way ofexample and not by way of limitation. The description will clearlyenable one skilled in the art to make and use the invention, describesseveral embodiments, adaptations, variations, alternatives, and uses ofthe invention, including what we presently believe is the best mode ofcarrying out the invention.

Referring to the drawings, and particularly FIGS. 1-3 inclusive, theremovable laryngeal mask of the present invention is shown generally at20. The laryngeal mask 20 comprises an inflatable positioning shield 22secured to the distal end 24 of a respiratory tube 26, forming a smootharcuate curve as shown in FIG. 3. Composed of a flexible silicone-rubberpolymer, respiratory tube 26 has an elliptical cross-section (see FIG.1A), approximating, for ease of insertion, the shape of the human throatshown in FIG. 7. Capable of spreading radially, respiratory tube 26 canaccommodate the passage of cuffed endo-tracheal tubes and relatedmedical devices up to 8.0 French in diameter. The length of respiratorytube 26 is such that when the laryngeal mask 20 is properly positionedfor use within the oropharynx, the attachment end 28 of respiratory tube26 is located exterior to the oral cavity. The attachment end 28 of therespiratory tube 26 terminates in an unobstructed proximal lumen 30,providing a direct pathway through the respiratory tube 26 to the distalend 24 and distal lumen 32. In alternative embodiments, the attachmentend 28 may be fitted with adapters or connectors (not shown) suitablefor connection to a variety of medical devices, for example, lungventilation machines.

The distal end 24 is the continuous portion of respiratory tube 26 whichhas passed through an airtight peripheral seal 34 at the rear of theinflatable positioning shield 22, and into the shield recess 36. Thedistal end 24 terminates at an angle to its length, forming theelongated elliptically shaped distal lumen 32 open to the interior ofthe shield recess 36. The elongated lower surface of the distal endforms the shield support 37, and provides a semi-rigid structure ontowhich the positioning shield 22 is secured. Numerous ventilation lumen38 perforate the distal end 24 to provide alternate airways in the eventthe distal lumen 32 becomes obstructed during patient lung ventilation.The ventilation lumen 38 prevent the formation of a pressuredifferential between the shield recess 36 and flexible respiratory tube26. Absent a pressure differential, any object obstructing the distallumen 32 will not become inextricably lodged within the distal end 24.

The inflatable positioning shield 22 is composed of a wedge-shapedtoroid 40, and a pliable molded posterior base 42. Inflation of thetoroid 40 is accomplished by means of a conventional inflation device(not shown), forming an ovoid shape conforming to the approximateavailable space in the oropharynx region. The posterior base is securedlongitudinally in an airtight manner to the lower surface of the shieldsupport 37. The posterior base 42 forms an elongated and taperedhemisphere, best seen in FIGS. 2-4. Two semi-rigid raised runners 44formed of molded silicone rubber are positioned longitudinally parallelto each other along the lower surface of the posterior base 42. Duringinsertion of the laryngeal mask 20, the raised runners 44 guide theplacement of the inflatable positioning shield 22, aid in preventinglateral movement by fitting to the rear anatomy of the oropharynxregion, and facilitate placement by decreasing drag. In fluidcommunication with the posterior base 42, the annular toroid 40 issecured to the peripheral upper surface of the posterior base 42, andinflates simultaneously to form the shield recess 36. A tracheal notch46 is formed in the portion of the annular toroid 40 traversing thefront of the inflatable positioning shield 22, best seen in FIG. 1. Thetracheal notch 46 surrounds the trachea after proper positioning andinflation of the laryngeal mask 20, preventing lateral movement andcreating a better air-tight fit with the trachea.

During use, the laryngeal mask 20 is inserted through the oral cavitywith the annular toroid 40 fully deflated. The smooth arcuate curve ofthe combined respiratory tube 26 and positioning shield 22 ensuresproper positioning of the laryngeal mask 20 within the anatomysurrounding the laryngeal opening. Upon proper positioning, asdetermined by a resistance to further forward motion, the annular toroid40 is inflated as described above. When fully inflated, the annulartoroid 40 exerts sufficient pressure against the structures of theoropharynx to form a tight seal surrounding the laryngeal opening.Positioned within the shield recess 36, the distal lumen 32 is axiallyaligned with the laryngeal opening, permitting positive lung ventilationto be performed, or allowing endo-tracheal tubes or related medicalinstruments inserted through the respiratory tube 26 to exit the distallumen 32, directly aligned for passage into the laryngeal opening.

Removal of the laryngeal mask 20 is normally the reverse of theinsertion procedure described above. In some situations, however, it isdesired to remove the laryngeal mask 20 without simultaneously removingor dislodging endo-tracheal tubes or related medical devices passingthrough respiratory tube 26 into the laryngeal opening. Referringgenerally to FIGS. 8-13, removal of the laryngeal mask 20 under suchcircumstances is facilitated by means of a tube retainer, showngenerally at 48.

Tube retainer 48 comprises a connection adapter 50, a stylet rod 52, andan endcap 68. Connection adapter 50 is composed of a soft semi-rigidmaterial forming a truncated conical structure having four equidistantlypositioned longitudinal ventilation grooves 56. Each ventilation groove56 permits the passage of air around the connection adapter 50 afterinsertion within an endo-tracheal tube as shown generally in FIGS.11-13. The exterior surface of connection adapter 50 between eachventilation groove 56 is threaded with threads 60. Each thread 60 isangled and shaped so as to facilitate insertion of the connectionadapter 50 into an endo-tracheal tube by means of a longitudinallydirected force applied to the adapter, but to exert a resistive forceagainst the removal of connection adapter 50 from an endo-tracheal tubein opposition to an oppositely directed longitudinally applied force.Alternatively, the adapter may be screwed into place, and unscrewed, asdesired. The conical nature of the connection adapter 50 permits thetube retainer 48 to fit securely within the opening of a variety ofendo-tracheal tubes, ranging from standard size No. 6 through standardsize No. 8 tubes. The present invention may be adapted as desired toaccommodate larger and/or smaller tubes without departing from the scopeof the present invention. As the tube retainer 48 is inserted within theopening of an endo-tracheal tube, the increasing exterior diameter ofthe connection adapter 50 prevents insertion beyond a certain point,limited by the interior diameter of the endo-tracheal tube.

The connection adapter 50 is secured at its base to a disk-shapedadapter base 62. Stylet rod 52 is a semi-rigid, circular cross-sectionrod. The length of stylet rod 52 is sufficient to traverse the distancebetween a point external to a patient's oral cavity and the laryngealopening. During the insertion of the rod retainer 48 within anendo-tracheal tube or related medical instrument, the end of stylet rod52, external to the oral cavity, consists of a softer stylet cap 68. Ofcourse, rod 52 may be used separately as an intubating stylet for directvisualization by unscrewing connector adapter 50 from rod 52 and placingcap 68 into the trachea directly. The soft cap 68 is designed andconfigured to reduce potential tracheal trauma when used as anintubating stylet.

FIGS. 11-13 illustrate the use of the tube retainer 48 during removal ofan laryngeal mask 20. As described above, the use of a tube retainer 48prevents the displacement of any inserted endo-tracheal tubes duringremoval of the laryngeal mask 20. The connection adapter 50 of tuberetainer 48 is secured to the stylet rod 52 and passed through therespiratory tube 26. The connection adapter 50 partially enters theproximal opening of the inserted endo-tracheal tube 70 as shown in FIG.11. The length of the stylet rod 52 is sufficient to extend beyond theoral cavity after insertion within the endo-tracheal tube 70, allowingmanipulation of the tube retainer as needed to ensure a secureinsertion. As shown in FIG. 13, the laryngeal mask 20, may then beremoved from the oropharnyx without dislodging the endo-tracheal tube 70by sliding the laryngeal mask 20 along the tube retainer 48. Tuberetainer 48 allows force to be exerted through the stylet rod 52 andconnection adapter 50 on the endo-tracheal tube 70, resisting thetendency of the endo-tracheal tube 70 to withdraw from the laryngealopening as the laryngeal mask 20 is removed. Once clear of the oralcavity, the laryngeal mask 20 is simply slid over the stylet cap 68 onthe tube retainer 48, allowing the endo-tracheal tube to remain in placewithin the patient's laryngeal opening. The stylet is then removed byunscrewing it from the endo-tracheal tube.

In view of the above, it will be seen that all the objects and featuresof the present invention are achieved, and other advantageous resultsobtained. The description of the invention contained herein isillustrative only, and is not intended in a limiting sense.

I claim:
 1. A laryngeal mask of the type used to facilitate lungventilation and the insertion of endo-tracheal tubes or related medicalinstruments through a patient's laryngeal opening as used during generalanesthesia, intensive care, or critical patient care, comprising:aninflatable positioning shield formed to fit within a patient'soropharynx and seal around the circumference of the laryngeal opening,said shield having an inflatable annular toroid peripheral portion, acontoured rear portion, and a recessed front, the front of the distaledge of said inflatable positioning shield being notched to securelysurround the trachea after inflation, preventing lateral movement of thelaryngeal mask; and a flexible respiratory tube having an proximal endlumen, a gently curved tubular body of sufficient size to permit passageof endo-tracheal tubes, and related medical instruments, and a distalend passing through and secured to the proximal edge of said annulartoroid peripheral portion, said distal end terminating at a distal lumenwithin the recessed front of the inflatable positioning shield such thattubes and instruments passing through the flexible respiratory tube willbe directed into the laryngeal opening.
 2. The laryngeal mask of claim 1wherein the flexible respiratory tube and the inflatable positioningshield are gently precurved along the same arcuate curve such thatminimal bending of the flexible respiratory tube is required duringpositioning of the laryngeal mask around the laryngeal opening.
 3. Thelaryngeal mask of claim 1 wherein the flexible respiratory tube has anelliptical cross-section facilitating insertion of the laryngeal maskthrough the oral cavity.
 4. The laryngeal mask of claim 3 wherein theflexible respiratory tube is composed of a material with a lowcoefficient of friction to facilitate the delivery of endo-trachealtubes and related medical instruments through the flexible respiratorytube to the laryngeal opening.
 5. The laryngeal mask of claim 4 whereinthe material of the flexible respiratory tube because of its ellipticalshape and flexible nature can deform radially to allow passage ofendo-tracheal tubes and related medical instruments having largecircular cross sections, returning to the original ellipticalcross-section shape upon the removal of said endo-tracheal tubes andrelated instruments.
 6. The laryngeal mask of claim 1 wherein the distallumen of the flexible respiratory tube is angled to provide an elongatedelliptical channel extending substantially to the distal end of theinflatable positioning shield, said channel serving as a guide forendo-tracheal tubes and related medical instruments and as a supportstructure for the inflatable positioning shield, preventing the distalend of said inflatable positioning shield from bending during insertion.7. The laryngeal mask of claim 1 wherein the distal end of the flexiblerespiratory tube contained within the recessed front of the inflatablepositioning shield is perforated by a plurality of small diameter lumen,said small diameter lumen providing alternate air passageways to preventthe blockage of airflow from the laryngeal opening through the recessedfront and flexible respiratory tube in the event the distal lumen isobstructed.
 8. The laryngeal mask of claim 1 wherein the tubular body ofthe flexible respiratory tube is of sufficient length to permit theproximal end lumen to be disposed adjacent, but external to, the oralcavity and the distal end lumen to be disposed adjacent and external tothe laryngeal opening.
 9. The laryngeal mask of claim 1 wherein theproximal end lumen of the flexible respiratory tube is adapted forattachment to medical devices.
 10. The laryngeal mask of claim 1 whereinthe annular toroid peripheral portion of the inflatable positioningshield is inflatable with air to form an essentially gap-free enclosuresurrounding the laryngeal opening.
 11. The laryngeal mask of claim 10wherein the inflatable positioning shield is generally ovoid in shapeafter inflation, contoured to the anatomical structures found in theoropharynx region.
 12. The laryngeal mask of claim 1 wherein theinflatable positioning shield is secured in an air-tight manner to theexterior surface of the distal end of said flexible respiratory tubewhere it passes through the annular toroid peripheral portion into therecessed front.
 13. The laryngeal mask of claim 12 wherein the recessedfront of the inflatable positioning shield is in fluid communicationwith the distal lumen of said flexible respiratory tube.
 14. Thelaryngeal mask of claim 1 wherein the inflatable positioning shield isof sufficient size to enclose the laryngeal opening within the recessedfront and to fit securely within the oropharynx anatomy.
 15. A laryngealmask of the type used to facilitate lung ventilation and the insertionof endo-tracheal tubes or related medical instruments through apatient's laryngeal opening as used during general anesthesia, intensivecare, or critical patient care, comprising:an inflatable positioningshield formed to fit within a patient's oropharynx and seal around thecircumference of the laryngeal opening, said shield having an inflatableannular toroid peripheral portion, a contoured rear portion, and adistal front portion; and a flexible respiratory tube having an proximalend lumen, a gently curved tubular body of sufficient size to permitpassage of endo-tracheal tubes, and related medical instruments, and adistal end passing through and secured to the proximal edge of saidannular toroid peripheral portion, said distal end terminating at adistal lumen within the front of the inflatable positioning shield suchthat tubes and instruments passing through the flexible respiratory tubewill be directed into the laryngeal opening;wherein the contoured rearportion of the inflatable positioning shield is inflatable with air toconform to the rear anatomical surfaces of the oropharynx region and toexert sufficient pressure against said surfaces so as to securely retainthe laryngeal mask in place, the contoured rear portion of thepositioning shield having a plurality of parallel raised lengthwiserunners to facilitate insertion and positioning within the oropharynx,said runners exerting pressure against the back of the oropharynx andstabilizing the inflatable positioning shield around the laryngealopening and being positioned to reduce drag during insertion.
 16. Thelaryngeal mask of claim 15 wherein the raised lengthwise runners arecontinuous extensions of the contoured rear surface.
 17. A laryngealmask of the type used to facilitate lung ventilation and the insertionof endo-tracheal tubes and related medical instruments into thelaryngeal opening as needed during general anesthesia, intensive care,or critical patient care, comprising:an inflatable positioning shieldgently curved to fit securely within the anatomical structures of theoropharynx region when inflated, said positioning shield enclosing thelaryngeal opening within a recessed front, and having an inflatableannular toroid peripheral portion forming a seal around thecircumference of the laryngeal opening, a plurality of lengthwise raisedridges protruding from a contoured rear portion, and a notched distalend fitted to the trachea to prevent lateral motion of the inflatablepositioning shield after inflation within the oropharynx; and a flexiblerespiratory tube having an proximal end lumen, a gently curved tubularbody having an elliptical cross-section and sufficiently radiallydeformable to permit passage of endo-tracheal tubes and related medicalinstruments, and a perforated distal end passing through and secured inan air-tight manner to the proximal edge of said inflatable positioningshield, terminating at an angular distal lumen within the recessed frontof said inflatable positioning shield so as to be aligned axially withthe laryngeal opening upon insertion into the oropharynx.